Deposition methods

1. A deposition method, comprising: providing a substrate, the substrate comprising a first surface and a second surface; the first surface comprising monocrystalline silicon and the second surface consisting essentially of electrically insulative material; exposing the first and second surfaces to at least one semiconductor material precursor under conditions in which growth of semiconductor material from the at least one precursor over the first and second surfaces comprises a lag phase period prior to a growth phase, and under which it takes longer for the growth phase to initiate on the second surface than on the first surface; the exposing being conducted for long enough for the growth phase to occur on the first surface, but not for long enough for the growth phase to substantially occur on the second surface; and wherein: the exposing is conducted in a reaction chamber and comprises a pulse of the at least one precursor into the chamber followed by a purge to substantially entirely remove the at least one precursor from within the chamber; a sequence comprising two or more of the pulses is utilized to form a thickness of semiconductor material; and a different semiconductor precursor is flowed into the chamber during at least one of the two or more pulses relative to at least one other of the two or more pulses.

2. The method of claim 1 wherein no etchant suitable for etching the semiconductor material is within the reaction chamber between the pulses.

3. A deposition method, comprising: providing a substrate within a reaction chamber, the substrate having a first surface and a second surface; providing a first semiconductor material precursor having a first activation time associated therewith for forming first semiconductor material over the first surface and a second activation time associated therewith for forming first semiconductor material over the second surface, the second activation time being longer than the first activation time; providing a pulse of the first semiconductor material precursor within the chamber, the pulse being maintained in the chamber for a time longer than the first activation time associated with the first semiconductor material precursor and no greater than the second activation time associated with the first semiconductor material precursor to selectively form the first semiconductor material from the semiconductor material precursor over the first surface relative to the second surface, the first semiconductor material having a third surface; providing a second semiconductor material precursor having a first activation time associated therewith for forming second semiconductor material over the third surface and a second activation time associated therewith for forming second semiconductor material over the second surface, the second activation time associated with the second semiconductor material precursor being longer than the first activation time associated with the second semiconductor material precursor; and providing a pulse of the second semiconductor material precursor within the chamber, the pulse being maintained in the chamber for a time longer than the first activation time associated with the second semiconductor material precursor and no greater than the second activation time associated with the second semiconductor material precursor to selectively form the second semiconductor material over the third surface relative to the second surface, the third surface not being etched prior to the formation of the second semiconductor material over the third surface.

4. The method of claim 3 wherein the second semiconductor material is the same in composition as the first semiconductor material.

5. The method of claim 4 wherein the first and second semiconductor materials both consist of silicon.

6. The method of claim 5 wherein the first surface consists of monocrystalline silicon, and wherein the second surface is electrically insulative.

7. The method of claim 6 wherein the second surface consists essentially of silicon and one or both of oxygen and nitrogen.

8. The method of claim 3 wherein the second semiconductor material is different in composition from the first semiconductor material.

9. The method of claim 8 wherein one of the first and second semiconductor materials consists of silicon, and wherein the other of the first and second semiconductor materials consists of germanium.

10. A deposition method, comprising: providing a substrate, the substrate comprising a first surface and a second surface; the first surface comprising monocrystalline first semiconductor material and the second surface consisting essentially of electrically insulative material; first exposing the first and second surfaces to at least one semiconductor material precursor under conditions in which growth of second semiconductor material from the at least one precursor over the first and second surfaces comprises a lag phase period prior to a growth phase, and under which it takes longer for the growth phase to initiate on the second surface than on the first surface; the first exposing being conducted for long enough for the growth phase to occur on the first surface, but not for long enough for the growth phase to substantially occur on the second surface; the growth phase on the first surface forming the second semiconductor material over the first surface; the second semiconductor material having a third surface; second exposing the second and third surfaces to at least one semiconductor material precursor under conditions in which growth of third semiconductor material from the at least one precursor over the second and third surfaces comprises a lag phase period prior to a growth phase, and under which it takes longer for the growth phase to initiate on the second surface than on the third surface; the second exposing being conducted for long enough for the growth phase to occur on the third surface, but not for long enough for the growth phase to substantially occur on the second surface; the growth phase on the third surface forming the third semiconductor material over the third surface; and wherein there is no etching of the third surface between the first exposing and the second exposing.

11. The method of claim 10 wherein the third semiconductor material is the same in composition as the second semiconductor material.

12. The method of claim 11 wherein the second and third semiconductor materials both consist of silicon.

13. The method of claim 10 wherein the first surface consists of monocrystalline silicon, and wherein the second surface is electrically insulative.

14. The method of claim 13 wherein the second surface consists essentially of silicon and one or both of oxygen and nitrogen.

15. The method of claim 10 wherein the third semiconductor material is different in composition from the second semiconductor material.

16. The method of claim 15 wherein one of the second and third semiconductor materials consists of silicon, and wherein the other of the second and third semiconductor materials consists of germanium.